U.S. patent application number 12/426761 was filed with the patent office on 2009-08-13 for palm diesel with low pour point for cold climate countries.
Invention is credited to Yusof BASIRON, Cheng Sit FOON, Yung Chee LIANG, Choo Yuen MAY, Harrison Lau Nik NANG, Ma Ah NGAN.
Application Number | 20090199463 12/426761 |
Document ID | / |
Family ID | 40937680 |
Filed Date | 2009-08-13 |
United States Patent
Application |
20090199463 |
Kind Code |
A1 |
MAY; Choo Yuen ; et
al. |
August 13, 2009 |
PALM DIESEL WITH LOW POUR POINT FOR COLD CLIMATE COUNTRIES
Abstract
The processes of producing the low pour point palm diesel
particularly but not exclusively via esterification of C18, C18:1
and C18:2 mixed fatty acids with methanol or ethanol, or fractional
distillation of methyl or ethyl esters of palm oil, palm kernel oil
and palm oil products, or fractional distillation of methyl or
ethyl esters of palm oil, palm kernel oil and palm oil products,
followed by crystallisation, or crystallisation of methyl or ethyl
esters of palm oil, palm kernel oil and palm oil products, or
crystallisation of methyl or ethyl esters of palm oil, palm kernel
oil and palm oil products, followed by fractional distillation.
Inventors: |
MAY; Choo Yuen; (Kajang,
MY) ; FOON; Cheng Sit; (Kajang, MY) ; LIANG;
Yung Chee; (Kajang, MY) ; NANG; Harrison Lau Nik;
(Kajang, MY) ; NGAN; Ma Ah; (Kajang, MY) ;
BASIRON; Yusof; (Kajang, MY) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Family ID: |
40937680 |
Appl. No.: |
12/426761 |
Filed: |
April 20, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10465847 |
Jun 20, 2003 |
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12426761 |
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10440169 |
May 19, 2003 |
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10465847 |
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Current U.S.
Class: |
44/388 |
Current CPC
Class: |
C10L 1/19 20130101; C10L
1/1802 20130101 |
Class at
Publication: |
44/388 |
International
Class: |
C10L 1/19 20060101
C10L001/19 |
Claims
1. A process to synthesize a biodiesel for use in cold climate
countries from palm oil, palm kernel oil and/or products thereof
comprising: subjecting methyl or ethyl esters or mixtures thereof
from palm oil, palm kernel oil and/or products thereof to
fractional distillation at a pressure of 20 Pa to 50 Pa and a
temperature below 145.degree. C. to obtain a distillate portion and
a residue portion, wherein the residue portion is the
biodiesel.
2. A process to synthesize a biodiesel for use in cold climate
countries from palm oil, palm kernel oil and/or products thereof
comprising: subjecting methyl or ethyl esters or mixtures thereof
from palm oil, palm kernel oil and/or products thereof to at least
one stage of dry crystallization wherein the methyl or ethyl esters
or mixtures thereof are cooled to a crystallization temperature
ranging from 12.degree. C. to -10.degree. C. and held at the
crystallization temperature for 3 to 12 hours to obtain a residue
portion and a filtrate portion, wherein the filtrate portion is the
biodiesel.
3. A process to synthesize a biodiesel for use in cold climate
countries from palm oil, palm kernel oil and/or products thereof
comprising: subjecting methyl or ethyl esters or mixtures thereof
from palm oil, palm kernel oil and/or products thereof to at least
one stage of solvent crystallization wherein the solvent used is
alcohol and the methyl or ethyl esters or mixtures thereof are
cooled to a crystallization temperature ranging from 5.degree. C.
to -12.degree. C. to obtain a residue portion and a filtrate
portion, wherein the filtrate portion is the biodiesel.
4. The process as claimed in claim 3, wherein the solvent used is
methanol.
5. The process as claimed in claim 4, wherein the ratio of methanol
to methyl or ethyl esters or mixtures thereof is ranging from 1:1
to 3:1.
6. The process according to claim 1, wherein said biodiesel has a
pour point of -21.degree. C.
7. The process according to claim 2, wherein said biodiesel
comprises a mixture of methyl and ethyl esters.
8. The process according to claim 3, wherein said biodiesel has a
pour point of -33.degree. C.
9. The process according to claim 3, wherein said biodiesel
comprises a mixture of methyl and ethyl esters.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation of pending application Ser. No.
10/465,847 filed on Jun. 20, 2003, which is a Continuation-in-Part
of application Ser. No. 10/440,169 filed on May 19, 2003, which has
been allowed to go abandoned, the contents of all of which are
incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates to a biofuel with improved
cold temperature flow characteristics without any additives. More
particularly but not exclusively, it relates to an improved biofuel
as a substitute for petroleum diesel from palm oil, palm kernel
oil, palm oil products and palm kernel oil products.
BACKGROUND ART
[0003] Due to increased environmental consciousness, the concept of
using vegetable oil as a fuel has developed in recent years. In
Malaysia, biodiesel has been successfully derived from palm oil.
Patent No. PJ1105/88 has revealed a process of producing palm oil
methyl esters (palm diesel) from palm oil. Palm oil is converted
into palm oil methyl esters via transesterification and the derived
palm oil methyl esters or palm diesel have proven to exhibit good
fuel properties and are able to be used as a diesel substitute.
`Production and Evaluation of Palm Oil Methyl Esters as Diesel
Substitute` published in Elaeis Special Issue, November 1995, pp
15-25 discloses the fuel characteristics of palm diesel and also
its potential to be used as a diesel substitute.
[0004] However, palm oil methyl esters being evaluated of having
pour point of +15.degree. C. to +18.degree. C. has a limitation to
its usage or consumption as a fuel especially in cold climate
countries. Although palm diesel exhibits good fuel properties and
able to meet the fuel specifications, some problems arise when it
is used in low operational temperature. This is because the pour
point of palm oil methyl esters is +15.degree. C. to +18.degree. C.
Pour point is the temperature of the oil 3.degree. C. above the
point at which the test sample will not move when tipped out of the
horizontal.
[0005] The fluidity of a fuel in an engine or machine is very
important under all circumstances. When starting up an engine from
cold, it is vital that the mechanical parts are able to move freely
and there is no difficulty in transporting the fuel through lines
and pumps. Failure to do so will lead to blockage and the engine or
machine may become inefficient and inoperable.
[0006] When fuel is cooled to low temperature, it can undergo a
number of changes, namely solidification, solidification with the
formation of a precipitate of macrocrystals and solidification with
the formation of microcrystals, which swell, giving a crystalline
structure that traps the remaining oil. Under these environments,
restriction in the flow of the fuel occurs. Thus, good low
temperature flow characteristics (pour point) of a fuel is
essential to ensure smooth operation and to be suitable for various
applications. A fuel is necessary to have good pour point, which is
the temperature of the oil 3.degree. C. above the point at which
the oil will not move when tipped out of the horizontal. The pour
point of all samples were analysed using standard method ASTM D97.
The pour point should be below the operational temperature.
[0007] To improve the low temperature characteristics mentioned
earlier, pour point depressants are normally employed. They act
through surface adsorption on to the wax crystals. The resulting
surface layer of the pour point depressant inhibits the growth of
the wax and paraffin crystals. Thus, in the absence of long
inter-locking crystals or swollen particles, fuel can move freely.
However, these additives though blended into the fuel in small
quantity, they are costly.
SUMMARY OF THE INVENTION
[0008] The present invention relates to a biofuel with improved
cold temperature flow characteristics without additives (pour point
depressant). More particularly but not exclusively, it relates to
an improved biofuel as a substitute for petroleum diesel from palm
oil, palm kernel oil, palm oil products and palm kernel oil
products.
[0009] The present invention discloses the premium grade palm
diesel composition and its good low temperature properties.
Contrary to the palm oil methyl esters, the disclosed premium grade
palm diesel (biodiesel) will be suitable to be used in cold climate
countries.
[0010] The present invention also discloses the processes of
producing the said low pour point palm diesel particularly but not
exclusively via
[0011] esterification of C18, C18:1 and C18:2 mixed fatty acids
with methanol or ethanol;
[0012] fractional distillation of methyl or ethyl esters of palm
oil, palm kernel oil, palm oil products and palm kernel oil
products;
[0013] fractional distillation of methyl or ethyl esters of palm
oil, palm kernel oil, palm oil products and palm kernel oil
products, followed by crystallisation;
[0014] crystallisation of methyl or ethyl esters of palm oil, palm
kernel oil, palm oil products and palm kernel oil products;
[0015] crystallisation of methyl or ethyl esters of palm oil, palm
kernel oil, palm oil products and palm kernel oil products,
followed by fractional distillation.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention discloses methyl oleate (more than 98%
purity) and methyl linoleate (more than 98% purity) respectively or
a mixture containing high proportion of methyl oleate and methyl
linoleate (>90%) as a premium grade palm diesel. This premium
grade palm diesel can solve the pour point problem encountered when
palm oil methyl esters (consisting of C16 (45%), C18 (5%), C18:1
(39%) and C18:2 (11%) are used in cold climate countries.
[0017] Methyl oleate, a fraction from palm oil methyl esters not
only exhibits good fuel properties just like the palm oil methyl
esters but also possesses low pour point of -18.degree. C. Methyl
linoleate exhibits pour point of -39.degree. C. This pour point is
very much lower compared to that of palm oil methyl esters (mixture
of C16, C18, C18:1 and C18:2). Thus, it can be used in cold climate
countries or during low operational temperatures. Similarly, it is
found that a mixture containing high proportion of methyl oleate
and methyl linoleate e.g. C14 (0.5%), C16 (4.9%), C18:1 (83.6%) and
C18:2 (11.0%) also exhibits low pour point of -21.degree. C.
Whereas, a methyl esters mixture of C14 (0.6%), C16 (5.7%), C18
(2.0%), C18:1 (79.0%) and C18:2 (12.7%) exhibits pour point of
-15.degree. C. Methyl esters mixture of C14 (0.5%), C16 (6.3%), C18
(2.9%), C18:1 (74.6%) and C18:2 (15.7%) exhibits pour point of
-12.degree. C. While methyl esters mixture containing C14 (0.7%),
C16 (6.7%), C18 (0.4%), C18:1 (75.5%) and C18:2 (16.7%) exhibits
pour point of -9.degree. C.
[0018] While the normal grade palm diesel would be the normal palm
oil methyl or ethyl esters, (45% C16, 5% C18, 39% C18:1 and 11%
C18:2), which exhibit pour point of +15.degree. C. This grade is
not suitable to be utilised in cold countries as it will solidify
in cold countries. Whereas C18, C18:1 and C18:2 mixed methyl or
ethyl esters that has a pour point of below -15.degree. C. can be
used in cold climate countries.
[0019] The said mixture of methyl or ethyl esters exhibiting low
pour point can be produced, particularly but not exclusively via
(1) esterification of C18, C18:1 and C18:2 mixed fatty acids with
methanol and ethanol, or (2) fractional distillation of methyl or
ethyl esters from palm oil, palm kernel oil, palm oil products and
palm kernel oil products, or (3) fractional distillation of methyl
or ethyl esters of palm oil, palm kernel oil, palm oil products and
palm kernel oil products, followed by crystallisation, or (4)
crystallisation of methyl or ethyl esters of palm oil, palm kernel
oil, palm oil products and palm kernel oil products, or (5)
crystallisation of methyl or ethyl esters of palm oil, palm kernel
oil, palm oil products and palm kernel oil products, followed by
fractional distillation.
[0020] All methyl and ethyl esters mentioned could be obtained
through fractionation of methyl or ethyl esters of palm oil, palm
kernel oil, palm oil products and palm kernel oil products or via
esterification of the respective fatty acids and methanol or
ethanol respectively. The acid-catalysed esterification of
respective fatty acids (or mixed fatty acids cut) and methanol or
ethanol can be carried out to yield the methyl or ethyl esters
since fatty acids can be easily obtained from fat splitting of palm
oil. The C16 methyl or ethyl esters and C18, C18:1 and C18:2 mixed
methyl or ethyl esters can be obtained through fractionation of
methyl or ethyl esters of palm oil, palm kernel oil, palm oil
products and palm kernel oil products, either by fractional
distillation or crystallisation or integrated fractional
distillation and crystallisation under controlled pressure and
temperature i.e. fractional distillation followed by
crystallisation or crystallisation followed by fractional
distillation. The C16 methyl esters can be sold for oleochemical
uses. They can be used as feedstock for high quality white soap and
with further mild hydrogenation process, they can also be used as
feedstock for .alpha.-sulphonated methyl esters. The C18, C18:1 and
C18:2 mixed methyl or ethyl esters fraction having pour point that
meets the requirement (0.degree. C. to -33.degree. C.) can be used
in temperate countries as biofuel.
[0021] Other than deriving low pour point palm diesel from palm oil
methyl esters, the processes disclosed in this invention could be
adapted to the production of low pour point palm diesel from palm
kernel oil methyl or ethyl esters. Palm kernel oil methyl esters
consists of C6 (0.3%), C8 (4.4%), C10 (3.6%), C12 (48.3%), C14
(15.6%), C16 (7.8%), C18 (2.0%), C18:1 (15.1%) and C18:2 (2.9%).
Integrated processes of fractional distillation and
crystallisation, i.e. fractional distillation followed by
crystallisation or crystallisation followed by fractional
distillation would lead to the production of low pour point palm
diesel.
[0022] Crystallisation of methyl or ethyl esters of palm oil, palm
kernel oil, palm oil products and palm kernel oil products can be
done by
[0023] dry fractionation;
[0024] solvent fractionation;
[0025] under gradual cooling and controlled conditions.
[0026] Saturated methyl or ethyl esters i.e. methyl or ethyl
palmitate and methyl or ethyl stearate can be fractionated from the
unsaturated methyl or ethyl esters i.e. methyl or ethyl oleate and
methyl or ethyl linoleate via dry fractionation (crystallisation).
Fine crystals formed when palm oil methyl or ethyl esters were
subjected to gradual cooling and slow agitation. Upon subjecting
the suspension of fine crystals to membrane filtration, C16 and C18
methyl or ethyl esters with purity of at least 80% can be produced.
By subjecting the resultant fraction to second stage fractionation,
the purity of the saturated methyl or ethyl esters can be further
enhanced. The same approach can be used for the filtrate obtained
from the first stage fractionation to produce the high
compositional of methyl or ethyl oleate (C18:1 methyl esters) and
methyl or ethyl linoleate (C18:2 methyl esters) with minimal methyl
or ethyl palmitate (C16 methyl or ethyl esters) and methyl or ethyl
stearate (C18 methyl or ethyl esters) in order to produce palm
diesel with low pour point. The residue fractions obtained from
several second stage crystallisation of filtrate rich in
unsaturated methyl or ethyl esters are preferred to be combined and
subjected to further crystallisation. While the filtrate fractions
obtained from several second stage crystallisation of residue rich
in saturated methyl or ethyl esters are also preferred to be
combined and subjected to further crystallisation. Thus, in this
manner, there will be no loss of the starting material (methyl or
ethyl esters of palm oil, palm kernel oil, palm oil products and
palm kernel oil products).
[0027] The present invention also discloses another route of
fractionation, i.e. via solvent fractionation. Saturated methyl
esters ie. methyl or ethyl palmitate and methyl or ethyl stearate
can be efficiently fractionated from unsaturated methyl or ethyl
esters ie. methyl or ethyl oleate and methyl or ethyl linoleate.
Methanol, ethanol and isopropanol have been proven to be excellent
choices of solvent for the crystallisation of saturated methyl or
ethyl esters from the unsaturated methyl or ethyl esters. The
typical composition of unsaturated methyl esters fraction obtained
is 1-2% methyl myristate, 4-6% methyl palmitate, 0-1% methyl
stearate, 70-72% methyl oleate, 20-22% methyl linoleate and 0-1%
methyl arachidate. While the saturated methyl esters fraction
consists of 0-0.4% methyl myristate, 86-89% methyl palmitate, 6-7%
methyl stearate, 3-5% methyl oleate, 1-2% methyl linoleate and 0-2%
of methyl arachidate.
[0028] One aspect of the present invention discloses the
composition of methyl or ethyl esters (C8, C10, C12, C14, C16, C18,
C18:1 and C18:2 methyl or ethyl esters) carbon chain length of and
the respective pour point. The pour point depends very much on the
percentage of methyl or ethyl esters of different chain length. It
is found that a mixture containing high proportion of methyl oleate
and methyl linoleate e.g. C14 (0.5%), C16 (4.9%), C18:1 (83.6%) and
C18:2 (11.0%) also exhibits low pour point of -21.degree. C.
Whereas, a methyl esters mixture of C14 (0.6%), C16 (5.7%), C18
(2.0%), C18:1 (79.0%) and C18:2 (12.7%) exhibits pour point of
-15.degree. C. Methyl esters mixture of C14 (0.5%), C16 (6.3%), C18
(2.9%), C18:1 (74.6%) and C18:2 (15.7%) exhibits pour point of
-12.degree. C. While methyl esters mixture containing C14 (0.7%),
C16 (6.7%), C18 (0.4%), C18:1 (75.5%) and C18:2 (16.7%) exhibits
pour point of -9.degree. C. Low pour point palm diesel can also be
achieved if and only if the mixture of methyl or ethyl esters of
palm oil, palm kernel oil, palm oil products and palm kernel oil
products has (1) less than 10% of total saturated methyl or ethyl
esters i.e. C14 methyl or ethyl ester, C16 methyl or ethyl ester
and C18 methyl or ethyl ester (2) at least 90% C18:1 and C18:2
mixed methyl or ethyl ester.
[0029] Besides exhibiting low pour point, the C18, C18:1 and C18:2
mixed methyl or ethyl esters also exhibit other fuel properties
(viscosity, flash point, sulfur content, gross heat of combustion,
conradson carbon residue, specific gravity and boiling point)
similar to those of petroleum diesel, thus indicating its
suitability as a diesel substitute. The overall performance of the
C18 mixed methyl esters is also being tested in stationery engines
and field trials.
The following examples further illustrate the present
invention.
Example 1
[0030] The premium grade palm diesel has pour point
.ltoreq.15.degree. C., depending on its composition.
[0031] Mixture of methyl esters, namely methyl myristate (0.5%),
methyl palmitate (4.9%), methyl oleate (83.6%) and methyl linoleate
(11.0%) exhibit low pour point of -21.degree. C. This methyl esters
mixture was obtained via acid-catalysed direct esterification of
technical grade of oleic acid (with purity 80%) with methanol.
[0032] Mixture of methyl esters synthesized with 0.6% methyl
myristate, 5.7% of methyl palmitate, 2.0% methyl stearate, 79.0%
methyl oleate and 12.7% methyl linoleate has a pour point of
-15.degree. C. Therefore, these mixtures of C18, C18:1 and C18:2
methyl esters can be utilised in temperate countries when the
operational temperature dropped to below 15.degree. C.
Example 2
[0033] Mixtures of C18, C18:1 and C18:2 methyl esters can also be
obtained through vacuum fractional distillation of palm oil methyl
esters (consisting of C16 (45%), C18 (5%), C18:1 (39%) and C18:2
(11%). At pressure of 30 Pa, 90% methyl palmitate was fractionated
out at 139.degree. C. followed by mixtures of C18, C18:1 and C18:2
methyl esters at 154-156.degree. C. This fraction of methyl esters
exhibits pour point of below 0.degree. C.
Example 3
[0034] Another possible route to produce different grade of palm
diesel is by using partial vacuum fractionation of palm oil methyl
esters. Under pressure of 25 Pa and temperature ranging between
145.degree. C. to 154.degree. C., mixture of methyl esters
consisting 6.0% methyl palmitate, 8.5% methyl stearate, 69.5%
methyl oleate and 16.0% methyl linoleate was obtained. This
fraction of methyl esters exhibits pour point of below 0.degree.
C.
Example 4
[0035] Crystallisation of palm oil methyl esters was carried out
using one part by weight of palm oil methyl esters in two parts by
weight of methanol. Bulk of C16 methyl esters crystallised out from
palm oil methyl esters when cooled down from 22.degree. C. to
-12.degree. C. in two stages. The remaining unsaturated (C18:1 and
C18:2) mixed methyl esters has a pour point of -33.degree. C. This
unsaturated mixed methyl esters consist 1.6% of methyl myristate,
5.0% methyl palmitate, 0.7% methyl stearate, 72.9% methyl oleate,
19.4% methyl linoleate and 0.4% methyl arachidate.
Example 5
[0036] Crystallisation of palm oil methyl esters was carried out
using one part by weight of palm oil methyl esters in two parts by
weight of methanol. The mixture was cooled to +5.degree. C. in 30
minutes. The mixture was filtered using suction filtration to
collect both the residue and filtrate. The filtrate was then
subjected to second stage crystallisation, where it was cooled to
-11.degree. C. in 2.5 hours. The filtrate after this stage consists
high percentage of unsaturated methyl esters, e.g. 70-72% C18:1
methyl esters and 20-22% C18:2 methyl esters. The filtrate exhibits
pour point of -12.degree. C. The residue collected from the first
stage of crystallisation was washed with some cold methanol
(+5.degree. C.) in order to get high percentage of saturated methyl
esters.
Example 6
[0037] Solvent crystallisation of distilled palm oil methyl esters
using methanol as solvent can also be carried out by one step
chilling. The mixture was cooled to -9.degree. C. in 2 hours. After
suction filtration, the filtrate collected contains 68-69% C18:1
methyl ester and 18-19% C18:2 methyl ester; and exhibits pour point
of -9.degree. C.
Example 7
[0038] Crystallisation of palm oil methyl esters was carried out
using one part by weight of palm oil methyl esters in two parts by
weight of ethanol. In the first stage of crystallisation, the
mixture was cooled to +3.degree. C. in 30 minutes. While in the
second stage of crystallisation, the filtrate was cooled to
-9.degree. C. in 2.5 hours. After filtration, filtrate with high
percentage of unsaturated methyl esters, e.g. 63-64% C18:1 methyl
ester and 15-16% C18:2 methyl esters was obtained and the pour
point is 0.degree. C.
Example 8
[0039] Crystallisation of palm oil methyl esters was carried out
using one part by weight of palm oil methyl esters in three parts
by weight of methanol. In the first stage of crytallisation, the
mixture was cooled to +2.degree. C. in 1 hour. While in the second
crystallisation, the filtrate was then cooled to -12.degree. C. for
2.5 hours. After filtration to remove the residue, high percentage
of unsaturated methyl esters, e.g. 71-72% C18:1 methyl ester and
18-19% C18:2 methyl esters. This mixture exhibits pour point of
-12.degree. C. Meanwhile, the residue collected from the first and
second stage crystallisation was washed with cold methanol in order
to get high purity of saturated methyl esters, e.g. 91-92% C16
methyl ester and 6-7% C18:0 methyl esters.
Example 9
[0040] Crystallisation was carried out for the fractions obtained
from partial fractional distillation. A fraction consists of 3.4%
C16 methyl esters, 8.8% C18 methyl esters, 71.6% C18:1 methyl
esters and 16.2% C18:2 methyl esters was cooled down from
+26.degree. C. to 0.degree. C. in 30 minutes crystallisation in a
water bath of -5.degree. C. One part by weight of methanol was used
for one part by weight of the mentioned fraction was used. The
residue consists of 5.6% C16 methyl esters, 84.0% C18 methyl
esters, 5.8% C18:1 methyl esters, 1.2% C18:2 methyl esters and 3.4%
C20 methyl esters.
Example 10
[0041] Crystallisation of a fraction consisting 0.3% C12 methyl
esters, 2.2% C14 methyl esters, 64.5% C16 methyl esters, 2.1% C18
methyl esters, 24.7% C18:1 methyl esters and 6.2% C18:2 methyl
esters was carried out in a water bath at -5.degree. C., cooling
from +26.degree. C. to +5.degree. C. in 20 minutes. This process
produced residue which consists 0.9% C14 methyl esters, 91.5% C16
methyl esters, 1.6% C18 methyl esters, 5.1% C18:1 methyl esters and
0.9% C18:2 methyl esters. One part by weight of methanol was used
for one part of weight of fraction.
Example 11
[0042] Crystallisation of a fraction consisting 0.3% C12 methyl
esters, 2.2% C14 methyl esters, 64.5% C16 methyl esters, 2.1% C18
methyl esters, 24.7% C18:1 methyl esters and 6.2% C18:2 methyl
esters was carried out in a water bath at -5.degree. C., cooling
from +26.degree. C. to +5.degree. C. in 3 minutes. This process
produced residue with composition of 0.9% C14 methyl esters, 91.4%
C16 methyl esters, 2.1% C18 methyl esters, 4.7% C18:1 methyl esters
and 0.9% C18:2 methyl esters. Two parts by weight of methanol was
used for one part by weight of fraction. Meanwhile, the filtrate
consists of 10.7% C16 methyl esters, 4.5% C18 methyl esters, 68.6%
C18:1 methyl esters, 15.6% C18:2 methyl esters and 0.6% C20 methyl
esters; and exhibits pour point of -6.degree. C.
Example 12
[0043] Dry crystallisation of a fraction consisting 0.3% C12 methyl
esters, 2.2% C14 methyl esters, 64.5% C16 methyl esters, 2.1% C18
methyl esters, 24.7% C18:1 methyl esters and 6.2% C18:2 methyl
esters was carried out in a water bath at -5.degree. C., cooling
from +25.degree. C. to +10.degree. C. in 5 minutes. This process
produced residue with composition of 1.5% C14 methyl esters, 83.0%
C16 methyl esters, 2.0% C18 methyl esters, 11.4% C18:1 methyl
esters and 2.1% C18:2 methyl esters. Meanwhile, the filtrate
consists of 10.5% C16 methyl esters, 2.4% C18 methyl esters, 70.2%
C18:1 methyl esters, 16.1% C18:2 methyl esters and 0.8% C20 methyl
esters; and exhibits pour point of -6.degree. C.
Example 13
[0044] Dry fractionation of palm oil methyl esters consists of C14
(1.0%), C16 (45.0%), C18 (4.1%), C18:1 (39.9%), C18:2 (9.7%) and
C20 (0.3%) was carried out under gradual cooling from +40.degree.
C. to +8.degree. C. in 15 hours and held at that temperature for 3
hours. Upon filtration of the crystals suspension by membrane
filter press, the resultant residue consists of C14 (0.8%), C16
(86.0%), C18 (1.8%), C18:1 (8.8%) and C18:2 (2.6%), i.e. 88.6%
saturated methyl esters and 11.4% unsaturated methyl esters. While
the filtrate consists of C12 (0.7%), C14 (2.0%), C16 (25.0%), C18
(2.4%), C18:1 (53.6%) and C18:2 (15.9%) and C20 (0.4%), i.e. 30.5%
saturated methyl esters and 69.5% unsaturated methyl esters; and
exhibits pour point of 6.degree. C.
Example 14
[0045] Dry fractionation of palm oil methyl esters consists of C14
(1.0%), C16 (45.0%), C18 (4.1%), C18:1 (39.9%), C18:2 (9.7%) and
C20 (0.3%) was carried out under gradual cooling from +40.degree.
C. to +9.degree. C. in 6 hours and held at that temperature for 12
hours. Upon filtration of the crystals suspension by membrane
filter press, the resultant residue consists of C14 (0.9%), C16
(79.7%), C18 (1.9%), C18:1 (13.5%) and C18:2 (4.0%), i.e. 82.5%
saturated methyl esters and 17.5% unsaturated methyl esters. While
the filtrate consists of C12 (0.7%), C14 (2.1%), C16 (25.1%), C18
(2.4%), C18:1 (53.2%) and C18:2 (16.0%) and C20 (0.5%), i.e. 30.8%
saturated methyl esters and 69.2% unsaturated methyl esters; and
exhibits pour point of 6.degree. C.
Example 15
[0046] Second stage of dry crystallisation on the residue or the
saturated methyl esters was carried out using the residue obtained
from a process as described in Example 14 to improve the purity.
The filtrate which consists of C14 (0.9%), C16 (79.7%), C18 (1.9%),
C18:1 (13.5%) and C18:2 (4.0%), i.e. 82.5% saturated methyl esters
and 17.5% unsaturated methyl esters was subjected to gradual
cooling from +40.degree. C. to +24.degree. C. in 4.5 hours and held
at that temperature for 2.5 hours. Upon filtration of the crystal
suspension by membrane filter press, the resultant residue consists
of C14 (0.3%), C16 (95.2%), C18 (1.0%), C18:1 (2.7%) and C18:2
(0.8%), i.e. 96.5% saturated methyl esters and 3.5% unsaturated
methyl esters. The residue which was high in saturated methyl
esters (96.5%) was further subjected to mild hydrogenation process
(pressure less than 50 MPa and temperature less than 300.degree. C.
using conventional catalyst such as Nickel). The resultant product
has an iodine value less than 0.5 and can be used as feedstock for
.alpha.-sulphonated methyl esters. While the filtrate consists of
C12 (0.3%), C14 (2.1%), C16 (68.6%), C18 (2.4%), C18:1 (20.6%) and
C18:2 (6.0%), i.e. 73.4% saturated methyl esters and 26.6%
unsaturated methyl esters.
Example 16
[0047] Dry fractionation of palm oil methyl esters consists of C14
(1.0%), C16 (45.0%), C18 (4.1%), C18:1 (39.9%), C18:2 (9.7%) and
C20 (0.3%) was carried out under gradual cooling from +40.degree.
C. to +12.degree. C. in 15 hours and held at that temperature for 3
hours. Upon filtration of the crystals suspension by membrane
filter press, the resultant residue consists of C14 (0.7%), C16
(87.9%), C18 (1.6%), C18:1 (7.7%) and C18:2 (2.1%), i.e. 90.2%
saturated methyl esters and 9.8% unsaturated methyl esters. While
the filtrate consists of C12 (0.7%), C14 (1.9%), C16 (32.1%), C18
(2.4%), C18:1 (48.3%) and C18:2 (14.3%) and C20 (0.3%), i.e. 37.4%
saturated methyl esters and 62.6% unsaturated methyl esters; and
exhibits pour point between 9 to 12.degree. C. The filtrate was
subjected to a second stage dry crystallisation.
Example 17
[0048] Second stage of dry crystallisation on the filtrate or the
unsaturated methyl esters was carried out using the filtrate
obtained from a process as described in Example 16 to improve the
purity. The filtrate which consists of C12 (0.7%), C14 (1.9%), C16
(32.1%), C18 (2.4%), C18:1 (48.3%) and C18:2 (14.3%) and C20
(0.3%), i.e. 37.4% saturated methyl esters and 62.6% unsaturated
methyl esters was subjected to gradual cooling from +40.degree. C.
to +2.degree. C. in 13 hours and held at that temperature for 6
hours. Upon filtration of the crystals suspension by membrane
filter press, the resultant residue consists of C12 (1.0%), C14
(1.6%), C16 (54.0%), C18 (2.8%), C18:1 (31.3%) and C18:2 (9.3%),
i.e. 59.4% saturated methyl esters and 40.6% unsaturated methyl
esters. While the filtrate consists of C12 (0.8%), C14 (2.2%), C16
(17.8%), C18 (2.3%), C18:1 (58.9%) and C18:2 (17.7%) and C20
(0.3%), i.e. 23.4% saturated methyl esters and 76.6% unsaturated
methyl esters; and exhibits pour point of 3.degree. C.
Example 18
[0049] One mole of technical grade of oleic acid (with fatty acid
composition of 0.5% C14, 5.5% C16, 80.2% C18:1 and 13.8% of C18:2)
was esterified with six moles of methanol at 160.degree. C. A 0.5
weight percent of concentrated sulphuric acid was used as catalyst.
After 4.5 hours of reaction, the crude product was water washed
until the decanted aqueous layer was neutral. The dried product was
subjected to second stage of esterification (re-esterification).
The esterification steps were similar to the first stage
esterification, except 0.3 weight percent of catalyst was used. The
resultant methyl esters from the first and second stage
esterification exhibit pour point of -15.degree. C. and -21.degree.
C. respectively.
Example 19
[0050] A fraction obtained from crystallisation with composition of
C14 (0.3%), C16 (95.2%), C18 (1.0%), C18:1 (2.7%) and C18:2 (0.8%),
i.e. 96.5% saturated methyl esters and 3.5% unsaturated methyl
esters was subjected to further fractional distillation and/or
hydrogenation process (pressure less than 50 MPa and temperature
less than 300.degree. C., using conventional catalyst such as
Nickel). This integrated process managed to produce C16 methyl
esters and/or C16 and C18 mixed methyl esters with purity more than
97% and iodine value less than 0.5. The resultant product is
suitable to be used as feedstocks for .alpha.-sulphonated methyl
esters.
Example 20
[0051] Second stage of dry crystallisation on the filtrate or the
unsaturated methyl esters was carried out using the filtrate
obtained from a process as described in Example 16 to improve the
purity. The filtrate which consists of C12 (0.7%), C14 (1.9%), C16
(32.1%), C18 (2.4%), C18:1 (48.3%) and C18:2 (14.3%) and C20
(0.3%), i.e. 37.4% saturated methyl esters and 62.6% unsaturated
methyl esters was subjected to gradual cooling from +40.degree. C.
to -4.degree. C. in 16 hours and held at that temperature for 6
hours. Upon filtration of the crystals suspension by membrane
filter press, the resultant residue consists of C14 (1.5%), C16
(46.5%), C18 (3.9%), C18:1 (37.5%) and C18:2 (10.6%), i.e. 51.9%
saturated methyl esters and 48.1% unsaturated methyl esters. While
the filtrate consists of C12 (0.8%), C14 (2.0%), C16 (8.5%), C18
(1.6%), C18:1 (67.9%) and (19.2%), i.e. 12.9% saturated methyl
esters and 87.1% unsaturated methyl esters; and exhibits pour point
of -9.degree. C.
Example 21
[0052] Second stage of dry crystallisation on the filtrate or the
unsaturated methyl esters was carried out using the filtrate
obtained from a process as described in Example 16 to improve the
purity. The filtrate which consists of C12 (0.7%), C14 (1.9%), C16
(32.1%), C18 (2.4%), C18:1 (48.3%) and C18:2 (14.3%) and C20
(0.3%), i.e. 37.4% saturated methyl esters and 62.6% unsaturated
methyl esters was subjected to gradual cooling from +40.degree. C.
to -10.degree. C. in 16 hours and held at that temperature for 6
hours. Upon filtration of the crystals suspension by membrane
filter press, the filtrate consists of more than 90.0% unsaturated
methyl esters; and exhibits pour point of -24.degree. C.
Example 22
[0053] A methyl esters fraction obtained from crystallization and
consists of methyl esters of C12 (0.7%), C14 (2.1%), C16 (25.1%),
C18 (2.4%), C18:1 (53.2%) and C18:2 (16.0%) and C20 (0.5%) was
subjected to fractional distillation. At pressure of 20-50 Pa and
temperature below 145.degree. C., C16 methyl esters was distilled
over and the remaining methyl esters consists of more than 90%
C18:1 and C18:2 methyl esters exhibits pour point of -21.degree.
C.
Example 23
[0054] The C18, C18:1 and C18:2 mixed esters not only has low pour
point but also exhibit good fuel properties that are comparable to
palm oil methyl esters. TABLE 1 the tabulated fatty acid
composition of the mixed methyl esters and its respective fuel
properties are tabulated in the TABLE 2.
TABLE-US-00001 TABLE 1 Fatty Acid Composition (as % weight methyl
esters) of C18, C18:1 and C18:2 Mixed Methyl Esters. Fatty Acid
Composition Methyl Esters (as % weight methyl esters) Methyl
Palmitate (C16) 4.2 Methyl Stearate (C18) 0.4 Methyl Oleate (C18:1)
81.6 Methyl Linoleate (C18:2) 13.8
TABLE-US-00002 TABLE 2 Fuel Properties of C18, C18:1 and C18:2
Methyl Esters, Palm Diesel and Malaysian Diesel Methyl Esters (C18,
C18:1 & Malaysian Test Palm Diesel C18:2 mixture) Diesel*
Specific Gravity 0.8700 @ 0.8803 @ 0.8330 @ ASTM D1290 74.5.degree.
F. 60.degree. F. 60.degree. F. Sulfur Content (% wt) 0.04 0.04 0.10
IP242 Viscosity @ 40.degree. C. (cSt) 4.5 4.5 4.0 ASTM D445 Pour
Point (.degree. C.) 16.0 -15.0 15.0 ASTM D97 Gross Heat of
Combustion 40,335 39,160 45,800 (kJ/kg) ASTM D2332 Flash Point
(.degree. C.) 174 153.0 98 ASTM D93 Conradson Carbon Residue 0.02
0.1 0.14 (% wt) ASTM D198 Distillation (.degree. C.) 324.0 282.2
228 Initial Boiling Point ASTM D86 *sample obtained from PETRONAS
petrol kiosk
* * * * *